A 17-year-old was knocked unconscious before being stabbed multiple times in the neck, arms and torso in a suspected gang incident in Porirua last night, police say.
The dispute appeared to be over a particular colour being worn by one of the men involved.
Emergency services were contacted about people fighting in the vicinity of Waitangarua Mall at 10.43pm.
Police said the confrontation was between two 17-year-old males.
"As a result of the confrontation one of the men was knocked unconscious and stabbed multiple times to his torso, arms and neck," a statement said.
He was today in a serious condition in Wellington Hospital's intensive care unit.
A police dog tracked the alleged offender to a nearby address.
He was found on the roof of a building where he had disposed of the knife.
A scene examination was underway.